Volcanic 'super-eruptions' more frequent than thought

Up to now, it was assumed that eruptions of this magnitude took place every 50,000 to 700,000 years, according to a study, published in the journal Earth and Planetary Science Letters.

The new estimate establishes a range of 5,000-48,000 years, with a best estimate of these type of eruptions occurring every 17,000 years on average, the lead author Jonathan Rougier told AFP.

"We find that super-eruptions - at least 1,000 billion tonnes of erupted matter - are much more frequent than previously thought," he said by email.

Explosive volcanoes on that scale dramatically lower Earth's temperatures and could darken skies to the point where most vegetation would struggle to grow.

Up to now, it was assumed that eruptions of this magnitude took place every 50,000 to 700,000 years, according to a study, published in the journal Earth and Planetary Science Letters.

The new estimate establishes a range of 5,000-48,000 years, with a best estimate of these type of eruptions occurring every 17,000 years on average, the lead author Jonathan Rougier told AFP.

"We find that super-eruptions - at least 1,000 billion tonnes of erupted matter - are much more frequent than previously thought," he said by email.

Explosive volcanoes on that scale dramatically lower Earth's temperatures and could darken skies to the point where most vegetation would struggle to grow.

Rougier's analysis covered a relatively short time span of 100,000 years.

Statistically speaking, this reduces uncertainty because scientists are more likely to identify nearly all of the eruptions during that period.

"As we go back further, the difficulty with interpreting the geological record becomes more acute, because more eruptions will be missed," he explained.

The findings do not mean that our planet is "overdue" for a devastating eruption, Rougier cautioned. 

"What we can say is that volcanoes are more threatening to our civilisation than previously thought."

Independent experts praised the study's methodology and endorsed its findings. 

"It turns out that these 'super-eruptions' are still very rare events, but just not quite as rare a previously thought," said David Pyle, a volcanologist at the University of Oxford.